Short-circuiting device



May 11 1926. 1,584,064

E. M. WRIGHT SHORT. CIRCUITI NG DEVICE Filed June 26, 1924 E] :1 met at Patented May 11, 1926..

EDWIN M. WRIGHT, 0F SPRINGFIELD, OHIO, ASSIGNOB TO THE ROBBINS dc MYERS COMPANY. OF SPRINGFIELD, OHIO, A CORPORATION 015 OHIO.

snoar-cincurrme Davide.

Application filed June 26,-

My invention relates to short circuiting devices for the armature windings of single phase induction motors,- particularly of the type which employs centrifugal balls as the means for operating-the devices.

Qne of the objects of my invention is to provide a device of the character referred to which will be simple in construction, economical in manufacture, easily installed and effective in operation. I

A further and more specific object of the invention is to provide an arrangement for imparting a quick or snappy action to the movable parts of the devices both when the contacts are moved into engagement with the commutator bars and also out of engagement therewith, this arrangement being such that the short ci-rcuiting devices will be held out of operative position with rela tion to the bars until a comparatively high speed is attained and the contacts will be held in engagement with the bars until a comparatively low speed is attained so that the short circuiting devices operate from one position to another upon a comparatively wide. diiierence in-speeds.

A further object of the invention is to provide a device of the character which can be assembled as a unit so as to be easily installed and removed, and of such a character that the number of centrifugally operated balls may be readily increased or diminished when desired.

In the accompanying drawings: a

Fig. '1 is an elevation of a portion of the armature and its shaft showing the commutator and short circuiting devices mounted thereon inv vertical section.

Fig. 2 is an elevation of one side of the ball container.

Fig. 3 is an elevation of one side of the operating disk.

Fig. 4 is an elevation of one side of the contacting disk.

Fig. 5 is an elevation of one side of the ball spacing disk.

Fig. 6 is an elevation of the key for the spring collar. V 4

Referring to the drawings, 1 represents a portion of the armature, 2 a portion of its shaft, 3 the commutator ring, and 4 the commutator bars. Mounted upon the shaft is a sleeve 5, this sleeve projecting into a recessed portion 3 of the ring 3 and being clamped to the ring by a nut 6 on a threaded 1924. Serial No. 722,587.

portion 1 oi:" the armature shaft; one or more fabric washers 7 being inserted between the ring and sleeve so as to properly 'lhe weight retaining disk is provided with an annular channeled portion 11 so-formed as to provide a snug nest for a series of Weights shown in the present case as steel balls 12 which are located in the pockets 10 of the spacing disk 10 so as to provide tor a balanced arrangement of the weights;

Slidably mounted upon the sleeve 5 between its inner end and the collar 8 is a second outer sleeve 13. ,The outer end of this outer sleeve 13 is reduced so as to form an inner shoulder and mounted upon this reduced portion is an operating disk l iand a contact disk 15 radially slotted to provide a series of contacts 15, the two disks 14 and 15 being clamped to the shoulder by upsetting or swaging the end of the sleeve 13, as indicated at 16. Between the disk 15 and a cupped collar 17 is a coiled spring18; the collar being placed upon the outer sleeve 5 against a U-shaped key 19 which is slipped into a milled slot in the sleeve. This coiled spring serves to hold the operating disk 14. in operative relation with the balls 12, the arrangement being such that at slow speed or when the parts are at rest the contacts are removed from the ends of the commutator bars as shown in Fig. 1.

Outwardly beyond the channelled portion 11 of the disk 9, the disk is formed with an inclined surface 20 which is approached by an annular ridge or hump 21 which ridge lies I immediate adjacent the outer boundary of the channel portion 11. Beyond the inclined portion 20, the disk has an annular retaining portion 22 the interior. surface of which is parallel with and concentric with the axis of the armature shaft. 7

In operation, after the motor is started the weights 12 will be held to their seat in the channel ll-by the sharp incline formed by the ridge 21 until the motor has acquired a comparatively high speed whereupon centrifugal force will move the weights over the ridge or hump 21 and thus force the contacts 15 into engagement with the ends of the commutator bars, the weights moving to the outer side of this ridge or hump so asto be held from return movement until the speed of the motor has become comparatively low. When the weights move outwardly over the ridge 21 it will" cause the contacts to be quickly thrown to contacting position because of the comparatively sharp inclination of the ridge and as the weights pass over the ridgeupon their return inward movement under the action of the spring the same thing will happen, thus causing a quick snappy-makeand-break contact between the contacts and the ends of the commutator bars.

The short circuiting devices are assembled as. a unit upon the sleeve 5 and held in position by the nut 6' so that the device may be readily removed from the armature shaft when desired. "When it is desiredto adjust for different speeds this is done by decreasing or diminishing the number of centrifugallyoperated weights. This may be accomplished by removing the nut 6 and slipping the entire short circuiting assembly 0d the armature shaft whereupon by removing the key 19 the-operating disk 14 may be moved away from thebweights so that additional balls may be insertedor some of the weights removed as desired.

Having thus described my invention, I

claim: a

1. In a short circuiting device, the combination, of an armature shaft and commutator, of a removable sleeve on said shaft to gether with means for locking the same thereon, a weight retaining member connect ed with said sleeve, means for holding weights in spaced relation in said member, a spring pressed operating disk movably mounted on said sleeve and cooperating with said weights so as to be moved on said sleeve by the centrifugal action of said weights,

said disk also serving to hold said weights in said member and, 'means for releasing said operating disk from said sleeve whereby said disk may be moved away from said Weights to permit Weights to be inserted o removed from said member.

2. In a short circuiting device, the combination, with an armature shaft and a com- 'mutator, of a sleeve removably mounted on spring whereby said disk may be moved away from said weights to permit weights to be removed from said member or additional balls added thereto. I

lln. testimony whereof, l have hereunto set my hand this 16th day of June, 1924.

EDWIN M. WRIGHT. 

